Acupuncture needles are extremely thin, no thicker than two human hairs. The needles have no resemblance to a hypodermic syringe. The needles are individually packaged, sterilized, and disposed of after each use. Most needles are inserted just beneath the skin. Sensations vary from person to person, ranging from nothing at all to a brief ache or feeling of pressure in the area being needled. Some points are more sensitive than others. By and large patients describe the sensations as fleeting and the treatment experience as deeply relaxing.